If it reaches the 1st of Jan you might it to be still last years date.
select
convert(date, DATEADD(yy, DATEDIFF(yy, 0, DATEadd(day, -1,getdate())), 0), 103 ) AS StartOfYear,
convert(date, DATEADD(yy, DATEDIFF(yy, 0, DATEDIFF(day, -1,getdate()))+1, -1), 103 )AS EndOfYear